Varnished cambric



Aug. 24, 1937. I DAMITZ 2,090,623 I VARNISHED CAMBRIC Original Filed April 11', 1934 KfilT EIKN IT IT IJKNIT EIK {/02 EIKNIT EIKNIT @4 F gj p I NVENTOR.

fi i f z fi ATTORNEY.

Patented Aug. 24, 1937 I Y I v V UNITED STATES PATENTOFFICE' VARNISHED CAMBRIC- Frederick M. Damitz, Irvington, N. J., assignor to Irvington Varnish & Insulator 00., Irvington, N. J., a corporation of New Jersey Qriginal application-April 11, 1934, Serial No.

720,150. Divided and this application November 4,1935, Serial No. 48,258

4 Claims. (Cl. ill-67.9)

This invention relates, generally, to varnished as substitution products. Among these substicambrics and the invention has reference, more tution products are water, glycerine, acrolein, particularly, to a novel improved varnished camaldehydes, non-volatile acids, and volatile fatty bric for use as insulation for cables and for other acids, which latter are further sub-divided into 5 purposes requiring a high quality insulating mathe water soluble and insoluble fatty acids. The. 5 terial, the said varnished cambric being designed Water soluble fatty aci s are ctro ytic and i for ready identification as to its source at any therefore conductors; alfld hence lower e electime. This application is a division of my 00- trical resisting pro i of e va ished earnpending application, Serial No. 720,150. bric. I

0 There has been a long felt need in the electrical Furthermere, the p s t on which-the film l0 cable business for a varnished cambric having s thr u u tsin h p du ti n of a p us means for readily identifying the source of the structure Which c e pa of absorbing a cambric or the cable manufacturer, and possesslarge proportion of moisture and at the-same time ing high dielectric strength, high insulation rethe film becomes brittle; Thu the yellow sistance and a high dielectric constant, the said nish fi is entirely of all oxidizing nature and varnished cambric to have a low power factor, is Continually tending to disintegrate. Although as well as possessing great water resistance, heat the e w varnish fi is translucent and hence resistance and oil resistance. can be seen through for reading identifying in- The principal object of the present invention is dicia 0 the C y Owing to the rapid to provide a novel varnished cambric having the deterioration of this fi and to its relatively above recited desirable qualities, the varnish film D insulating qualities, the same does not rate of the cambric being translucent so that identias a high grade insulating materialfying indicia or other markings on the cambric Black va d cambrics a d by coating are easily legible. cambric with an insulating varnish composed of Another object of the present invention lies in inert black non-oxidizing asphaits and pitches in the provision of a varnished cambric of the above combination with drying Oiis- T sp a d character having a varnish film comprising transpitches are decidedly better insulators or dieleclucent asphaltic material in combination with tries han t y l w s and resins or the d ylinseed and China-wood oils, ing oils themselves. The varnish filmsor coat- Other objects of this invention, not at this time in s of h e k varnished ri r black 30 more particularly enumerated, will be clearly un-. and p q however, so it s impossible o Ne derstood' from the following detailed description y e indieia 0n the h i t be s n thr u hv of the same. thefilm. Furthermore, attempts to print or Varnished cambrics as heretofore manufa otherwise mark identifying indicia onthe outer tured may be classified'in two classes depending Surface of the varnished film of the cambric a 3 on their color, whether yellow or black. Y ll met with failure because of the ease with which varnished cambrics are quite generally made by such ki s or indieia u Off in coating cambric with an all drying oil. In some Th method f m rkin n v rn hin my rare instances small amounts of gums and resins va ed Cambric is Clearly illustrated in the 40 are added to the drying oil, but such additions cflmpanying d s, in W V o tend to make the varnish film brittle and hence Fi 1 is a schematic v w f pl n d for are seldom used. The drying oil used in produeproducing the varnished cambric of this invening yellow varnished cambrics is generally a comtion.

bination of China-wood oil and linseed oil and Fig. 2 is an enlarged seetionalview taken alongwhen these oils dry out and oxidize the film li e of 45 formed goes through two phases. Fig. 3 is an enlarged fragmentary plan view" During the first phase, i. e., when the varnish of the printed cambric. is changing from a liquid to a solid, it is absorbing Fig. 4 is an enlarged view taken along line oxygen without the elimination of any other prodo ucts. If, after the varnish has completely satu- Fig. 5 is an enlarged fragmentary plan view 50 rated itself with oxygen, the reaction ceased, it of the finished varnished cambric, and would be an ideal condition, but such is not the Fig. 6 is an enlarged sectional view taken along case for as long as the dxidized film is in contact line 6-6 of Fig. '1. r

with the air it continues to react with oxygen by Similar characters of reference are employed 65 taking on oxygen and splitting ofi radicals known in said views, to indicate corresponding parts.

In carrying out my invention, I print, stencil or otherwise mark the cambric or base cloth with suitable identifying characters, such as the trade-mark of the cable manufacturer or that of the varnished cambric manufacturer and then coat the printed cambric with the novel varnish of this invention. In preparing this varnish I use transparent or translucent material such as intermediate grades of cottonseed oil pitch hav- 1o ing a viscosity range of from to 30 degrees MacMicheal, i. -e. when'employing MacMicheal viscometer and using a No. 27 wire' and a two centimeter bob at 25 C., the 'cottonseedpitch having been thinned somewhat with a mineral spirit such as Varnolene. If desired, instead of using cottonseed oil pitch I may use linseed oil pitch, fish oil pitch, wool wax pitch, wool oil pitch, decolorized pitches such as those bleached with sulphur chloride, and various cashew shell oil combinations. These pitches when cooked with oils into varnishes, produce a finished .transe lucent'or substantially transparentiproduct varying in color from a dark yellow, to a deep brown and gin some instances to a'reddish brown. s

dients are used in t he -pe'rcentages given by In producing the varnish I mix 200 lbs. cottonseed oil pitch (60% solid and %unineral spirit, viscosity range from 10 to 30 MacMicheal, i. e. by'MacMicheal viscometer using a No. 27 wire and a two centimeter bob at 25 C) with B'gallons of linseed oil and .heat the mixture to approximately 600F. This hot mixture is kept at 600 'F. for from one to two hours during which period polymerization and some oxidation takes place, thereby incr asing the viscosity of the mixture and giving t e same the desired body. During this heating period, themlxture may be blown with either air, nitrogen or carbon dioxide thereby hastening polymerization, although such blowing is not necessa I Six pounds of litha ge serving as aidrier is then added and mixed thoroughly into the hot pitch-oil mixture.- Twenty gallons of Chinawood oil is also added with stirring. The cold China-wood oil will cause the temperature of the 'pitch-oil-litharge mixture to drop considerably so the mixture is then heated somewhat to bring its temperature up to approximately 540 F.

thereto 8 more gallons of.China-wood oil and then held for body at 450 F., after which 14 lbs.

of manganese resinate serving as a drier is stirred into the mixture. The varnish base thus formed is allowed to cool somewhat and when at a temperature oi! from 300 to 350 F. the same is thinned with 100 gallons of "Varnolene (a petroleum hydrocarbon or mineral spirit having a distillation range of 310 to 420 F.). The novel varnish is now-complete and is of brownish color and when applied in the form of a him and allowed to dry the same forms a smooth, flexan example of the novel varni'shgernployed in/the present invention, the following ing'reafter'which the mixture is chilled by adding ible, durable and substantially transparent In producing the varnished'cambric of this invention, a web I (see Figs. land 2) of cambric, fed from a roll 2 is passed over a printing roll 3 that is supplied with in]: as by an inking roll 4. The printing roll 3 serves to print the desired indicia I0 such as a trade name or manufacturer's name on the web I which web may be a plain cambric, a colored cloth, or a fabric provided with a design or designs thereon. The thusly printe'd' fabric is shown in Figs. 3 and 4.

After leaving the printing roll I, the web I is passed through the novel varnish I of this invention which varnish is contained in,a pan '0 mounted in a vertical heating tower I. If de- 'jsired, the varnish may be further thinned by use'of Varnolene" 'or any other mineral spirit such as naptha, benzene, toluol, benzol, xylol and high flash naptha before passing the web I therethrough. After emerging from the varnish 5, the web passes upwardly within the vertical heating tower I, the air within 'whichis main- 'tained at a temperature of from 280 to 330 1''. as by heating coils I. The web is shown passing overa roll I2 at the top of tower I and then downwardly through more varnish I contained within a second pan 6. From the pan the web passes upwardly and over a roll I3 at the top of the tower and then downwardly and out of the tower. Within the tower I the solvent is driven oil of the varnished cambric and the varnish is oxidized and polymerized After leaving the tower I, the varnished web I, having the varnished film or coating II on its outer surface,

is rolled on a roll 9.

Although in Fig. 1, I have shown the web as dipped but twice, ordinarily the web would bedipped three, four or'even more times to build up the desired thickness of film II, and after each dip the web is dried within the heating tower. Thus, for a 12 mill finished product, using a 4 mill cloth, the web will be dipped four times, having the varnish at about 30- Baum for the first .coat and 35 Baum for the subsequent coats, usingflvarnolene'? as a solvent 'for thinning. If desired, instead oi dipping the. fabric, the varnish may be sprayed, brushed or roller coated thereon.

The varnished cambric thus produced has exceptionally high insulating qualities and the .translucent or substantially transparent fllm or coating II enables the indicia II to be readily legible as illustrated in Fig. 5. Tests show that the dielectric strength of this novel varnished cambric to be 20 to 30% higher than yellow varnished cambrics and the insulation resistance at room" temperature is 10 ,or substantially one thousand times as great as that of yellow varnished cambrics. At 100 C. the insulation resistance is 10' times that of the yellow. The 41- electric constant of this novel varnished cam-' bric is approximately 4 as compared to 5% to 6 for yellow varnished cambric. At room temperature, the power factor of my varnished cambrie is of the magnitude of about 3%% as compared to 10 to 12% for yellow varnished cambric. At 60C. the power factor of my varnished cambric is of the magnitude 014 to 5% as compared with 30% for yellow varnished cambric, while at C. the power factor-oi my cambric is 5 to 7% as compared to 70'to for yellow varnished cambric. My varnished cambric also shows superiority over yellow varnished cambric as to water and heat resistance. After 21 hrs. 01'

immersion in water the yellow varnished cambric will have absorbed 12 to 15% of its volume oi. water and its dielectric strength will be reduced about 60%, whereas my cambric after a like immersion will absorb but 4 to 5% of its volume of water and its dielectric reduced but 30 to 40%.

Black varnished cambrics as heretofore produced have higher insulating properties than the yellow varnished cambrics, but since these black varnished cambrics have opaque films they are not suitable for my purpose where a substantially transparent film is desired in order to read indicia on the web or cambric and hence I have made no comparison between the insulating properties of black varnished cambrics and my varnished cambric.

The cottonseed oil pitch ingredient 01' my varnish composition serves to stabilize the linseed oil and the China-wood oil and effectively prevents these ingredients from excessive oxidation. It appears that the pitch serves as a matrix for surrounding the oxidizing oils, 1. e. linseed and China-wood oil, so that these oils do not come into contact with sumcient oxygen to produce excessive oxidation.

It will be understood that some variation may be made in the relative percentage of the several ingredients of my varnish composition while still retaining the high insulating qualities of the same and the same transparency or translucency whereby the indicia may be read. The percentages of the oils should not be unduly increased, however, because they will then decrease the electrical resisting properties of the varnish and render it less moisture proof. Too much pitch on the other hand willdecrease the flexibility of the film and will lower its resistance to oil solubility (i. e. transformer oil for example).

If desired, instead of using cottonseed oil pitch I may use linseed oil pitch, fish oil pitch, wool wax pitch, wool oil pitch, decolorized pitches such as those bleached with sulphur chloride and cashew shell oil combinations. These pitches should be thinned, if necessary, so as to have substantially the same viscosity range as that of the cottonseed oil pitch.

It is to be understood that I may use quantities of other oils partly in lieu of or in addition to the linseed oil and China-wood oil in my varnish.

For example, I may add quantities of the following oils, namely perilla oil, soya bean oil, cottonseed oil, rapeseed oil, fish oil, paramn oils and higher grease oils. I

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, as defined by the following claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:-

I. A varnished cambric comprising, a base cloth having indicia marked thereon and a substantially transparent varnish overlying said base cloth and said indicia, whereby said indicia may be seen through said varnish, said varnish constituting a combination of a drying oil and a substantially transparent vegetable oil pitch, said varnish having high insulating efiiciency.

2. A varnished cambric comprising, a base cloth having indicia marked thereon and a substantially transparent varnish overlying said base cloth and said indicia, whereby said indicia may be seen through said varnish, said varnish comprising a drying animal oil and a substantially transparent pitch, said pitch serving as a matrix for the drying oil.

3. A varnished cambric comprising, a base cloth having indicia marked thereon and a substantially transparent varnish overlying said base cloth and said indicia, whereby said indicia may be seen through said varnish, said varnish comprising a mixture ,of linseed oil and Chinawood oil as a drying oil and substantially transparent cottonseed oil pitch, said pitch serving as a matrix for the drying oil.

4. In a varnished cambric having a base cloth provided with markings thereon, a substantially transparent varnish film overlying said base cloth and said indicia, said varnish film comprising a mixture of linseed oil and China-wood oil as a drying oil and a substantially transparent cottonseed oil pitch having a viscosity range 01' from 10 to 30 percent MacMicheal and serving as a matrix for the drying oil.

FREDERICK M. DAMITZ. 

